1. Field of the Invention
The present invention relates to an object, a method, or a manufacturing method. Further, the present invention relates to a process, a machine, manufacture, or a composition of matter. In particular, the present invention relates to a semiconductor device, a display device, a light-emitting device, a method for driving any of them, or a method for manufacturing any of them, for example. In particular, the present invention relates to a semiconductor device including an oxide semiconductor, a display device including an oxide semiconductor, or a light-emitting device including an oxide semiconductor, for example.
Note that in this specification, a “semiconductor device” generally refers to a device which can function by utilizing semiconductor characteristics; an electrooptic device, a light-emitting display device, a semiconductor circuit, and an electronic device are all included in semiconductor devices.
2. Description of the Related Art
A technique by which transistors are formed using semiconductor thin films formed over a substrate having an insulating surface has been attracting attention. The transistor is applied to a wide range of electronic devices such as an integrated circuit (IC) or an image display device (display device). A silicon-based semiconductor material is widely known as a material for a semiconductor thin film applicable to a transistor. As another material, an oxide semiconductor has been attracting attention.
For example, Patent Document 1 discloses a transistor in which an amorphous oxide semiconductor film containing indium (In), gallium (Ga), and zinc (Zn) is used as an active layer and regions of the oxide semiconductor film to which hydrogen is added are included as a source region and a drain region.
Further, Patent Document 2 discloses a transistor in which regions of an amorphous oxide semiconductor film to which nitrogen is added are included as a source region and a drain region.